Anything trying to display the whole chain is one example, like some every logging library or custom output in existence. For behavior: sometimes wrapping orde

Anything trying to display the whole chain is one example, like some every logging library or custom output in existence. For behavior: sometimes wrapping order matters, and As is convoluted to use to determine that, to say the least. Manually unwrapping is easy, and reasonably safe and easy - the standard library does it! But...